I designed and built these button pins as an art contribution to the BaconWood festival. BaconWood is a bacon and music festival that takes place in the Mendecino woodlands. 100 of these were distributed to the crowd, making this giant bacon party more colorful and blinky.

The MCU controls each LED individually with 4bit PWM. I built a pattern framework which allows for different types of patterns (blinking, twirling, random, ...). The framework can do various thing like palette animation, color ranges, operate at different speeds and so on.

The idea was to make a cool little pin in itself, but also to design a cheap modular node that can be network to one another to use for other projects. In other words, these pins can be meshed into a network. Each one can receive, emit or retransmit patterns.

The board is made so that there's a 4 pins connector on either side. The 4 pin connector is (VCC, GND, IO, IO), where IO is a bidirectional UART. I wrote a software UART using a simple protocol and interuptions on these IO pins. The message is typically a lighting pattern, validation and timing as to when to pass the pattern to the next neighbor.

I designed the PCB using Eagle, the PCB were printed by AP Circuits, the parts ordered from DigiKey, the LEDs from somewhere in China, and the whole was hand soldered by yours truly (yes, it did take a million hours).

These pin can be assembled in strings or meshes. I have 100 left. Stay tuned to see what I'm going to do with them.